Transmission and control mechanism



Aug.. 27, 1935.

F. A. PARSONS TRANSMISSION AND` CONTROL MECHANISM 4 Sheets-Sheet l Filed Feb. 28, 1929 a l l Flg. 2

ug. 27, 1935. Y F, A, PARSONS 2,012,690

TRANSMI SS ION AND CONTROL MECHANISM Filed Feb. 28, 1929 4 Sheets-Sheet 2 l 10s yo. 'n

qvENToR Aug. 27, 1935. F. A. PARSONS TRANSMISSION AND CONTOL MEGHNISM Filed Feb. 28, 1929 4 Sheets-Sheet 3 INvE R @wa/wv Aug. 27, 1935. F. A. PARSONS 2,012,690

l TRANSMISSION AND CONTROL MECHANISM Filed Feb. 28, 1929 4 sheets-sheet 4 F1. g. 8. i sa Patented Aug. 27, 1935 AUNI-'ran s'rxrasA Pii'llaii'rl OFFICE TRANSMISSION AND CNTROL" ItIECHANISM Fred A. Parsons, Milwaukee, Wis., assigner to Kearney & Trecker Corporation, West Allis,

Wis.

Application FebruaryA 28,1929, Serial No. 343,482

'39 Claims. (Cl. 90-21.5)

^ This invention is directed to transmission and control mechanism and more particularly'to such mechanism for machine tools and similar use.

A purpose of the invention is to provide an im trol means operable to permit the rate of a memf vber driven from a substantially constant-speed source, to be in part determined in accordance with the instantaneous operating conditions, rsuch asv the load resistance, and to the combination therewithv of means visibly indicating the actual rate of the driven member.

Other purposes relate to transmission and eontrol means capable o! operation to permit the rate of a driven member to be at least in part determined by the instantaneous operating conditions,

such as the load resistance, or to permit of operation in a mannerto maintain a predetermined, substantially constant rate in spite of variations in operating conditions; and to means for alternatively selecting the one or the other of such modes of operation which is necessary or desired for different operating conditions. V

Other purposes relate to improvements in a transmission which is in part iiuid operated, and to an improved control thereof, particularly o! the fluid operated portion. l f

Other purposes relate to improvements in a transmission having a fluid operated portion, and in control means for maintaining the rate of a member driven therefrom substantially constant in spite of variations in uid leakage caused by varations'in load resistance, or iiuid temperature, or viscosity, etcetera. I

Other purposes relate to improvements in a transmission havinga fluid operated portion capabie of adjustment for a change in rate-of a driven member, and to control nieansrfor adjusting such portion, andto means for maintaining substantfally constant the rate pre-selected by such adjustment, in spite of. variations in fluid leakage caused by variations in load resistance or fluid temperature orv viscosity, etc.

Other. purposes are to generally simplify and improve the construction and operationA of transmission and control mechanism, particularly for milling machines, and still other purposes will be apparent from this speciiication.

The invention consists of the construction and, combination of parts as herein` illustrated, de-

scribed and claimed, and in' such modification of 5 the structure illustrated and described as may be equivalent to the claims.

In the drawings, the same reference characters indicate the same parts in each oi the views, of which:

, lo Fig. 1 is a front elevation of a portion of a.v milling machine incorporating the invention.

Fig. 2 shows a partial right hand side elevation of the same machine. f

Fig. 3 is a partial vertical section' taken along w line 3 3 of Fig. 1 and enlarged.

Fig. 4 shows an enlarged plan view of a portion of the machine to the right in Fig. 1, omitting a work table positioned over the members shown.

Fig. 5 is a partial section taken along line 5-5 20 of Fig. 3.

Fig. 6 is an enlargedportion of Fig. 1. Figs. 6ft-,6b show sections through a reverser valve taken along line 6a-6a and 6b-6b of Fig. 6.

Fig. 7 shows a partial vertical section taken 2 along line I-'I of Fig. .1 and enlarged.

Fig. 8 is a diagrammatic view of certain of the transmission and control mechanism, arranged to. show operating relationship rather than the relative position of the parts.

-ment between spindle 5 and table 4 in three mutually transverse paths.

A transmission is provided for' spindle l as follows:

A pulley i, adapted to be actuated from a suitable exterior power source, provides a power source for the milling machine. Pulley 6 is xed on a sleeve 'I upon which is also fixed a member 8 of a. clutch generally denoted by the numeral 9, Fig. 2.

A shaft I0 has slidably keyed therewith a sleeve I I upon which is iixed another clutch member I2, the members 8-I2 having complementary friction faces at I3 which may be engaged or disengaged by movement of sleeve II.

Sleeve II may be moved for such purposes by l the means of a hand lever I4 fixed on a shaft I5 upon which is also fixed a lever I 6 which moves a lpivoted lever I1 by the means of a rod I8 having a pivoted engagement with the levers. Lever I'l provides a pi-voted shoe I8 engaging an annular groove 28 in the sleeve'll.

The shaft I 0, which may be connected or disconnected from the power source by the mechanism described, drives a shaft 2| through a rate changer generally denoted by the numeral 22, Fig. 2, and consisting in this instance of different diametered gears 23--24-25 fixed together and slidably keyed with shaft I8 for movement to engage one at a time with complementary gears 26-21-28 fixed on the shaft 2l. Shaft 2| drives spindle 5 through a pinion 29 fixed on the shaft and a gear 30 meshed with the pinion and fixed with the spindle.

A feed train for power movement of table 4 is driven from the spindle train at a point between the clutch 9 and the rate changer 22, as follows:

Fixed on sleeve I I is a gear 3|, Figs. 1-2, which drives agear 32 through an idler 33. Gear 32 is xed on a shaft 34 upon which is also xed the driving member 35 of an extensible universal joint shaft of well known construction and generally denoted by the numeral 36, Fig. 1. The driven member 31 thereof, Figs. 48, is fixed on a shaft 38 journaled in a housing 39, Figs. 1 2-7,

. fixed on saddle 3. and driving a fluid pump generally denoted by the numeral 48, Figs. 4-6-7-8. A uid motor for movement of table 4 from pump 4 0 consists in this instance of a piston 4I, Figs. 1-8, operating in a cylinder 42 and -having a piston rod 43 extending out of the cylinder at each end thereof and fixed at one or both ends with the table. The motor is operable from pump 48 through a reverser valve generally denoted by the numeral 44, Figs. 6-7-8.

P ump may be of any suitable form, but as here shown is of a construction similar to that fully shown and described in a United States Patent No. 1,678.050, issued July 24, 1928, and

will therefore be only briefly described.

The pump is retained within a substantially closed casing 45, Figs. 7 8, xed with housing 39 and having a removable cover portion 46 carrying a pump housing member 41. `Removably fixed thereon is a pump housing member 48. Portions of the housing members form trunnions respectively on opposite sides of a spherical chamber 43 having its center coinciding with the axis of shaft 38. Ports 58-5I, respectively for suction and exhaust, Ycommunicate with the chamber 49 through the trunnions. The trunnions mentioned .support ring members 52-53 fixed with a member I4, whereby the rings and member form a unit supported and guided for movement about Aan axis passing through the center of the spherical chamber and at right angles to the axis of shaft 36. Journaled in member 54 is a. shaft 55 having its axis at right angles to the axis'about which member 54 moves, and passing through the center of the spherical chamber in any position of member 54. Fixed on shafts 38-55 respectively are members 56--5'|. An intermediate member Il is pivoted both with member 56 and member 61, the respective pivots being aty right angles to one another and each passing through the center of the spherical chamber.

'Member 56, driven from shaft 38, drives the intermediate member 58, which inturn drives member 51 and shaft 55 and the arrangement, is

' 'such that when member 54 isA adjusted for shaft I5' to stand at an angle relative to shaft 38 there are formed within the spherical chamber four separate substantially closed chambers each of l which is alternately expanded and contracted during each revolution of the parts, and each of which is positioned by such rotation to communicate during expansion with the suction or inlet port 50, and during contraction with the pressure or o utlet port 5I whereby fluid is forced through the pump. The amount of volume change of the chambers during rotation and therefore the rate of fluid delivery from the pressure port is dependent upon. the adjustment of member 54; being zero when the member is adjusted for shaft to be in axial alignment with'shaft 38, Whereby the position of adjustment of the. member and shaft will determine the rate at which the piston 4I is moved and the table rate may be changed while maintaining the drive shaft 38 at a constant speed.

The channels leading from pump 40 to the cylinder 42 are as follows: Referring to Figs. 6-60-612-8, the pump ports 50-5I respectively ports adjacent the movable stem 6I of reverser valve 44. 'I'he channel 59 terminates in a portf 62, Fig..6b, and channel6ll terminates in a port 63, Fig. 6a. The ports 62-63 are respectively ad jacent the opposite ends of the movable valve stem 6I. Adjacent port 63 are ports 64-65 and adjacent port 62 vare ports 66-61. The ports 64-66 each communicate with a pipe or channel 68 leading to the right end-of the cylinder 42, Fig; 8, while the ports 65--61 each communicate with a channel or pipe 69 leading to the left end of the cylinder. The direction of rotation and all adjustments of pump 40 are such that fluid is expelled through pump port 5I, and valve stem 6I is cut away as shown in Figs. '6a-6b to lead the fluid when the valve is in the positionthere shown, from pump port 5I through channel 60, and valve port 63, through the valve stem to the valve port 65 and through channel 69 to the left end of the cylinder to move piston 4I and table 4 to the right. At the same time the cut .away valve portions connect the channels for the uid from the right end of the cylinder in Fig. 8 to be expelled through channel 68, valve ports 66 and 62, channel 59 to the pump inlet port 50. If the valve stem 6I is turned onequarter turn from the position shown in Figs. StL-6b, the connection of the pump inlet and outlet ports withthe cylinder will be reversed and the table will move the other direction. The ports 62-63 are made relatively large in order that an intermediate position of the valve stem will simultaneously open both ports 62,-63

to both channels 68-69 in whichcase the ports 62-63 will communicate with one another thus open into closed channels 59-60 which lead to by-passing pump 48 to stop the table. In such case the channels 68-69 are also freely connected, thus by-passlng the fluid from one side of the piston -to the other, whereby the table when not connected with its transmission may be moved by suitable manual means (not shown) 'I'he valve-stem 6I maybe shifted to effect either direction of table travel or tobring the table to a stop by the means of a hand'lever 10, Figs. 1-6-7, xed on a shaft 'I I upon'which is also fixed a bevel gear 12, engaging a bevel gear I3 fixed on the valve stem. The valve stem may also be shifted to neutral or intermediate position at a predetermined position of table movement by the lmeans of plungers 'I4- 15 respectively on opposite sides of the shaft 1I and engaging suitable angu- 'lar rack teeth on the plungers vwithgear teeth 16 `on the shaft. 'Ihe relation is such that movement of shaft 1| to engage either direction of table travel moves one of the plungers 14-15 upwardly, and in the course of the resulting travel the plunger may be contacted'by the one or the other of dogs 11-18 adjustably fixed on table 4, the plungers and dogs having complementary angular surfaces adapted to move the plunger back down again to position valve stem 8| in a motion interrupting position.

Pump 40 may be adjusted manually to determine the rate of table travel by the means of the following mechanisms. A hand lever 19, Figs. 1-3-6-8, is fixed on sleeve 80 rotatably xed in saddle 3. Also fixe-i on sleeve 80 is a bevel gear 8| engaging a pinion 82 fixed on a shaft 83. Fixed on shaft 83 is a worm 84 engaging a worm wheel 85 which forms a member of a differential device generally denoted by the numeral 86, and which includes the worm wheel 85, another worm wheel 81, normally prevented from movement by its engagement with a worm 88, a plurality of bevel gears 89-90 xed with the different worm Wheels respectively, a frame or spider 9| xed on a shaft 92 upon which the Wheels 8.5-81 are rotatably supported, and bevel pinions 93-94 each rotatably carried by frame 9| and each engaging both bevel gears 89-90.

'Ihe arrang ment is such that worm 84 may turn shaft 92 through the differential mechanism. Fixed on shaft 92 is a vgear 95 engaging a pinion 96 fixed on a shaft 91 upon which is also fixed a cam 98 having a cam groove 99 within which is a follower roll pivoted on a plunger or rod |0| having rack teeth |02 engaging suitable teeth |03 on the periphery of the pump ring 53. By the means of the described mechanism the pump members may be relatively adjusted to vary the volume of pump flow.

A pointer or indicator |04, Figs. 3 8, is movable relative to a chart or dial |05, Figs. i-3-8, in accordance with the movement of lever 19, the pointer being in this case fixed with the lever. 'I'he chart or dial |05 is preferably graduated to indicate rates of table travel which result from a given position of the hand lever and pump when The actual rate of table movement will, unless prevented, vary somewhat in accordance with such load resistance because of leakage in the pump and motor, and means are provided to indicate against the same chart or dial the actual instantaneous rate of the table.

Such means are as follows: Fixed with the table 4 is a rack |06, Fig. 3, engaging a pinion |01, Figs. 3-4-8, fixed on a shaft |08 upon which is also fixed a bevel gear |09 engaging a pinion I |0 fixed on a shaft whereby shaft is rotated at a relatively high speed in exact accordance with the movement of. table 4. A speed responsive device generally denoted by the numeral ||2 is driven from shaft and in this case consists of weights ||3-| I4 pivoted with retaining arms ||5| I6 pivoted with a member ||1 slidably keyed on shaft III, and with retaining arms |8| I9 pivoted with a member |20 fixed on shaft Weights ||3| I4 are normally drawn toward one another by springs |2| whereby to press member |1 to the left in Figs. 4 8 but when the table 4 is moved the shaft I rotates and in either direction of such rotation centrifugal force acting on weights ||3| |4 causes the weights to separate, and member |,|1 to move to the right by an amount proportional to the speed or rate of table 4.

Member l1 is connected to move a pointer or indicator |22 reading against the dial |05 as follows: A lever |23, having a fork |24 engaging an annular groove |25 in member I|1, is pivoted at |26 and an arm |21 engages suitable gear teeth thereon with circular rack teeth |28 on a slidably guided member-|29, which is adjustably fixed with a slidably guided member |30 by the lmeans of a threaded portion |3| and nut |32.

Member |30 has a portion |33 extended for suitable rack teeth thereon to engage a pinion |34 fixed on a shaft |35 journaled in an axial bore of sleeve 80 and having the indicating pointer 22 xed thereon.

The respective pointers |04|22 move in accordance with different mechanisms differently movable through the range of table movement corresponding to the dial graduations therefore the movement of one or both pointers must be corrected through at least a portion of the range of movement to suit the dial, since the dial can-- not be graduated to correspond with the uncorrected movement of both mechanisms. In this case the dial |05 is graduated in accordance with the movement of speed responsive device ||2 and pointer |22 and the mechanism connecting pointer |05 with pump 40 is provided with correcting mechanism consisting of the cam 98 previously described. Thus the pointers may each follow the same movement and by the means of the adjustment between the members I 2S and |30 they may be relatively adjusted to corresponding positions.

The arrangement is such that when there is no load resistance to table movement the pointer |04 will indicate against dial |05 the table rate resulting from any position of pump 40 and pointer |22 will move to a. corresponding position as soon as the table starts movement at that rate. But, unless prevented by mechanism later described the table movement will sloW down because of fluid leakage as soon as there is a load resistance, and in exact accordance with such resistance. In such case the pointer |22 will move to a position corresponding to the instantaneous actual table rate, while pointer |04 remains in its previous position and the two pointers together conveniently indicate not only the actual table rate irrespective of the setting of pump 40, but also the difference between the actual rate and the rate at no table load, whereby the instantaneous load on the table may be accurately estimated from such difference.

Mechanism is provided which if desired may be used to maintain a table rate corresponding to any position of pointer |04, irrespective of the table load, as follows:

A sleeve or member |36, Figs. 4-6-8, is slidabl fitted on the member |30, and is provided with two ports |31|38 respectively adapted to receive fluid from a channel or chamber |39 associated with member |30, as the member |30 is moved relative to member |36 in the one or the other direction. The ports |31|38 communicate through suitable channels such as fexible tubes |40|4| with opposite ends respectively of a cylinder |42 having a piston |43 and a piston rod |44 extended for suitable rack teeth thereon to engage with a gear |45 fixed o n a shaft |46 upon which is also fixed the worm 8B meshing with the worm wheel 81 of the differential mechanism 06 previously described.

The member |38 is arranged to move in accordance with the movement of pointer |04, by the means of a cam |41, fixed on the shaft 83 and a cam follower plunger |48 fixed with member |36 and moved by the cam in thel one direction and by a spring |49 in the other direction, whereby the position of member |36 at all times corresponds to the position of pointer |04. The cam |41 is congurated for such position alsol to correspond with the position which would be assumed by the member |36 if the table were traveling at a rate corresponding with the setting of pointer |04. But if the table is not traveling at such a rate, as for instance, when the table load resistance causes leakage of fluid in the table transmission, then the position of the member |30 does not correspond and there is relative dis'- placement between members |30-|36 in a drection corresponding to the amount of increase or decrease of actual table rate from the rate indicated by pointer |04.

'I'he arrangement is such that when both members |30- |36 are positioned in accordance with the position of pointer |04 neither of the ports |31-I38 receive fluid from chamber |39, but in the event that because of a variation of actual table rate from indicated table rate, the relative position of the members |30- |36 is changed, the one or the other port Will receive fluid according to the direction of such variation above or below the indicated rate. The fluid thus admitted to the ports shifts piston 43, the fiuidfrom the idle side of the piston being relieved at the same time to permit the piston to move, through recesses or channels |50 or |5| arranged in the member |30 to be opened to the inactive port by the same movement which renders the other port active. The piston in turn adjusts pump 40 through the differential mechanism and pump shifting train connected therewith as previously described. The direction of adjustment of pump 40 from the one or the other port 13T- |30 is such as to increase or decrease the table rate, whichever may be necessary to cause member |30 to be moved to correspond to the position of member |36 and pointer |04, and such pump adjustment will continue as long as the members |30-|36 are relatively displaced or in other words until the actual rate of table 4 corresponds to the rate indicated by pointer |04.

It will be noted that, although the main source of variations from desired table rate, when using a hydraulic table transmission, is due to changes resulting from changes in temperature of the fluid used, or leakage due to changes in pressure, yet the mechanism above described also acts to maintain the rate against variations from other causes or any cause, such as a slowing down of the main driving pulley for any reason.

In the operation of the machine it is sometimes preferable to permit the table rate to vary in accordance with load resistance andat other times preferable to maintain a predetermined constant rate. For this reason there is provided means whereby the rate maintaining mechanism just described may be selectively rendered operative or inoperative, as follows:

The shaft |46 is provided with locking means, consisting of a hand lever |52 fixed on a threaded stem |53 having an end portion adapted to engage and frictionally lock the shaft against movement. whereby the rate maintaining mechanism is ineffective to adjust pump 40. When the rate maintaining mechanism is inoperative, the worm wheel 81 of the differential mechanism 86 should occupy a predetermined position such that the adiustment of pump 40 produces the rate indicated by pointer |04 when there is no table resistance. Such position of worm Wheel 81 may vary somewhat according to the temperature and viscosity of the uid in the transmission but may be readily determined by rst setting the pointer |04 to some position productive of table movement, then with no load resistance on table 4 adjusting the pump 40 by the means of a hand crank (not shown) applied to the squared end |54 of shaft |46, until the table rate as indicated by pointer |22 corresponds to the rate indicated by pointer |04. The shaft |46 may then be locked by lever |52 to retain the Worm Wheel 81 in the position thus found.

Fluid under pressure may be supplied to the chamber |39 from any suitable source forl operation of the rate maintaining mechanism`but in this case is supplied as follows: l

A pump generally denoted by the numeral |55, Figs. 3-4-5-8 is driven from the spindle transmission at a point between the pulley 6 and clutch 9. The pump drive train consists of a gear |56, Fig. 2, fixed on clutch member 8 engaging a gear |51 xed on a shaft |58 upon which is also fixed the driving member |59 of an extensible universal joint generally denoted by the numeral |60 and having a driven member |6| fixed on the drive shaft |62 of the pump.

Pump |55 may be of any suitable type but in this case is of well known form consisting of gears i3-|64, Fig. 5, substantially enclosed within a casing or housing |65. The inlet port |66 communicates through a channel |61 with an inlet opening |68 submerged in fluid contained Within a reservoir formed by a housing or cover |69, Fig. 3, arranged to receive back all fluid used in the operation of the rate maintaining mechanism.

The outlet or pressure port |10, Fig. 5, communicates with an accumulator consisting of a variable volume chamber |1| formed by a spring pressed plunger |12 movable in a bore |13. The chamber 1| supplies fluid to the chamber |39 through a pipe or channel |14, a flexible tube |15, a.` channel |16 within the member |30 and an opening |11. The channel |61 communicating with inlet port |66 passes through the bore |13 in a manner such that the movement of plunger |12 closes the inlet channel when the accumulator chamber |1| has received a predetermined volume of fluid, sufficient to operate the rate maintaining mechanism through an ordinary rate correcting movement, and to prevent the fluid pressure in chamber |1| from reacting on the pump when the channel |61 is thus closed there is provided a check valve |18 consisting of a spring pressed ball |19 in the channel between the pump outlet port and chamber |1i. The described arrangement is such that the pump |55, although continuously running, consumes power only in substantial accordance With that required for the operation'of the rate maintaining mechanism, yet at all times there is instantly available sufficient uid for the normal requirement of such operation.

It will be noted that the only purpose in providing a manual pump adjustment from lever 19 is to provide for operation of the machine Without the operation of the power shifter which maintains a constant table rate. In the event that this alternative operation is not necessary, that is to say, if it is satisfactory to at all times control the table to maintain a constant predetermined rate irrespective of leakage or other factors tending to cause rate variation, then the control mechanism may be simplified by eliminating the connection from shaft 83 to the pump adjusting means.

What is claimed is:

1. Ina machine tool the combination of a work support, a tool support, a power source, a transmission connecting said power sourcefor movement of one of said supports and including rate change means adapted to vary the rate of said movement, and means visibly indicating the rate of movement of the last mentioned support, said means including a device having members rela,`

tively movable independently of said rate change means and in accordance with variations in the rate of said last mentioned support and speed indicating elements connectedfor relative movement from said device.

2. In a machine tool the combination of a Work support, a tool support, a transmission for movement of one of said supports, and means visibly indicating the rate of movement of the lastv mentioned support, said means including a device having members actuated for relative movement in accordance with the actual rate of movement of the last mentioned support, and speed indicating elements connected for relative movement from said device. v

3. In a machine tool the combination of a work support, a tool support, a transmission for movement of one of said supports including an adjustable 'rate changer, movable adjusting means therefor, means visibly indicating the position of said adjusting means, and means visibly indicating the actual rate of movement of the last mentioned support irrespective of the position of rate changer adjustment.y 4

4. In a machine tool the vcombination of a movable member, a transmission for actuating said member including a iiuid operable portion and an element driven therethrough, and means for visibly indicating the actual rate of movement of said member, said means including a device having a plurality of members actuated for relative movement from said element, and speed indicating elements actuated for relative move'- ment from said device, whereby changes in rate of said'member caused by changes in operating conditions of said machine tool may be visibly indicated as they occur.

5. In a machine tool the combination of a movable member, a transmission therefor including a fluid operable rate changer adjustable for the purpose of 'changing the rate of member movement and an element driven through said rate changer, movable adjusting means for said rate` adjustable rate change means, a first indicating device movable in accordance with the position of adjustment of said rate change means, a secmember from the rate normally corresponding to the adjustment of said rate change means.

7. In a'machine tool the combination of a movable member, a transmissiontherefor including` s an adjustable rate change means, a first movable rate indicating device,- a train connecting said device with said rate change means for movement in accordance with the adjustment thereof, a

second movable rate indicating device, a train l connecting said second device for movement-in accordance with the actual rate of movement of said member, said trainsncluding means establishing a rate indicating range of movement of one device to substantially correspond with the range of movement indicating corresponding rates in the other device.

8. In a machine tool the combination of a movable member, a transmission therefor including adjustable rate change means, and means automatically operative in accordance with changes in the rate of said^member to adjust said rate change means to maintain the rate of said member substantially at a predetermined value.

9. In a machine'tool the combination of a movable member, a transmission therefor including a hydraulic portion and an element driven there-' cldingi an adjustable rate changer and an elementdriven therethrough, means automatically operable in accordance with the rate of said element to adjust said rate changea/.whereby to maintain the rate of said member substantially at a predetermined value, and means alternatively adjustable fo'r said automatically operable means to be operative or inoperative. j

l1. In a machine tool thel combination o f a movable member, a transmission therefor ,in-

cluding a hydraulic portion and an element driven therethrough, said hydraulic portion being in part adjustable to change the rate of movement of said member, `means automaticallyoperable in accordance with changes in the rate of said element to adjust said adjustable part, whereby to substantially maintain a desired rate of said member, and means alternatively adjustable for said automatically operable means to be operative or inoperative.

12. In a machine tool, the combination of a movable member, a transmission therefore vincluding an adjustable rate changer, manual means for adjusting said rate changer, means for adjusting said. rate changer in accordance with the rate of said member, and means operative ,on said rate changer for the adjustment thereof from each ofY said adjusting means to select and maintain a desired rate in spite of variations in operating conditions.

13. In 'a machine tool the combination of a movable member, a transmission therefor including an adjustable rate changer, manual means for adjusting said ratechanger, means for adjusting said rate changer in accordance with the rate of said member, means operative on said rate changer for the adjustment thereof from each of said adjusting means, and means for selectiyely rendering said movable means operative or inoperative" while maintaining the operation of said manual means.

y 14. In 'a machine tool the combination of a movable member, a transmission therefor including an adjustable rate changer, manual niv means connected for adjusting said rate changer, means movable in accordance with changes in some of the operating conditions of said machine tool for adjusting said rate changer, a device visibly indicating the effect of said manual adjusting means, and a device visibly indicating the combined result of both said adjusting means.

15. In a milling machine the combination of a rotatable tool spindle, a work support movable relative thereto in a path transverse to the spin- ,dle axis, a transmission for said spindle, a train driven from said spindle transmission for movement of said work support and including a fluid operable portion in part adjustable for changing the rate of movement of said work support and also including an element driven through said iluid operable portion, and means automatically'operative in accordance with changes in the rate of said element to adjust said portion.

16. In a machine tool the combination of a movable member, a transmission therefor in- `*cluding a fluid operable portion in part adjustable for changing the rate of member movement and an element driven through said portion, said portion being subject to leakage variations substantially in accordance with ,the resistance to member movement, manual means adjustable for a desired rate of .said member, and means automatically operative in accordance with changes in the rate of said element to adjust said portion for substantially maintaining said desired rate in spite of said leakage variations.

17. In a milling machine the combination of a rotatable tool spindle, a work support movable relative thereto in a path transverse to the spindie axis, a transmission for said spindle, a power train for driving said support from said transmission and including a fluid operable portion in part adjustable for changing the rate of sup- 'port movement and an element driven through changer and including a fluid operable portion and an element driven therethrough, said fluid operable portion being adjustable to vary the rate of support movement, and a speed responsive device for visibly indicating the rate or si ,support and connected for operation from said power train through said element.

19. In a milling machine the combination of a rotatable tool spindle, a work support movable relative thereto in a path transverse to the axis of said spindle, a power source, a ton including a rate changer and driven from said power source to actuate said spindle, a power train driven from said source Ato actuate said support exclusive of said rate changer and including a fluid operable rate changer and a reverser, whereby the support may be actuated at a variety of rates determined by said fluid operable rate changer and in either direction of said path, and a speed responsive rate indicator adapted to indicate the rate of movement of said support and connected to be actuated from said power train through said iiuid operable rate changer and said reverser.

20. In a machine tool the combination of a movable support, a transmission for movement therefor including a fluid operable portion in part adjustable for changing the rate ofsupport movement, a first means shiftable for adjusting said portionto a position approximately productive of a desired rate of support movement, other means shiftable independently of said first means. for additionally adjusting said portion, and means for shifting said other means in accordance with changes in the rate of movement o'f said support.

2l. In a machine tool the combination of a movable support, a transmission for movement thereof including a fluid operable portion in part adjustable for changing the rate of support movement, a manual means for adjusting said portion l to a position approximately productive of a de- A sired rate of support movement, power means for additionally adjusting said portion, and control means for said power means and in part operative in accordance with the position of said manual means and in part operative in accordance with changes in the rate of movement of said support.

22. In a machine tool having a movable support the combination of a transmission for movement thereof including a. fluid operable portion in part adjustable for changing the rate of support movement, a power operated shifter for adjustment of said portion, and a control device for said shifter including a member manually shiftable to a variety of positions, and a member shiftable in accordance with changes in the rate of movement of said support, said device being operative in accordance with the relative position of said members.

23. In a machine tool the combination of a movable support, a transmission for movement thereof including a portion adjustable to change the rate of support movement and reversing means -in serial arrangement with said adjustable portion, a power operated shifter for adjustment of vsaid portion independently of the effect of said reversing means, and speed responsive means automatically controlling said power operated shifter in accordance with changes in the rate of movement of said element.

24. In a machine tool the combination of a movable support, a transmission for movement thereof including a fluid operable portion oppositely adjustable to increase or decrease the rate of support movement, a shifter including a device having opposite power movements respectively to adjust said portion in directions to increase and decrease the rate of support movement, means movable in the one or the other direction accordingly as the rate of support movement is lesser or greater than a predetermined rate, and a connection from said means for shifting said device.

25. In a machine tool the combination of a movable support, a transmission for movement thereof including a uid operable portion in part adjustable to change the rate of support move-l ment, a manually adjustable rate change device, a power operable shifter for adjustment of said portion, an element movable in accordance with the adjustment of said device, an element movable in accordance with the actual rate of support movement, and control means for said power operable shifter and'operable in accordance with' the relative positionof said elements.

movable support, a transmission therefor including a fluid operable portionI in part adjustable for changing the rate of support movement, manual means for adjustment ofvsaid portion, power operable means for adjustment of said portion, a power. source for said power operable means, a control device operable to determine the connection of said power source with said power operable means in accordance with the changes in the rate of movement of said Support whereby to maintain a predetermined rate of support movement, and means selectively adjustable to render said power operable means eective or ineffective.

27. In a machine tool, the combination of a movable member, a transmission therefor including adjustable rate change means and reversing means in serial relation and means automatically operative to adjust said rate change means, said means including a device operable in accordance with a change in some of the operating conditions of said machine tool, and a motion transmitting connection from said device to said rate change means-adapted to maintain the rate of said member substantially at a predetermined value in spite of said variations in operating conditions,

- said connection being` operative independently of the effect of said reversing means.

28. In a machine tool, the combination of a movable member, a transmission for actuating said member including reversing means, a iiuid operable motor, a pump, a iluid circulating system including a channel between said pump and motor containing iiuid under pressure and adjustable rate 'change means, power operable means for adjustment of said rate change means, control means for said power operable means including relatively movable elements, and means for relative movement of said elements and operable in accordance with changes in some od.' the operating conditions ofsaid machine tool, said means for element movement being operable for said movement independently of the effect of said reversing means. l

29. In a machine tool, the' combination of a movable member, a transmission therefor including a hydraulically operable portion adjustable for changing the rate of member movement, a manually operablemeans for adjusting said portion for a desired rate, and automatic means for adjusting said portion said automatic means including a device operable in accordance with a change in some of the operating conditions of said machine tool, and a motion transmitting connection adapted to adjust said portion to maintain said rate in spite of said change in operating conditions.

30. In a machine tool, the combination of a movable member, avtransmission therefor including a hydraulically operable portion adjustable f or changing the rate of member movement, a device having a plurality of elements each independently movable for the adjustment oi' said portion, manual means for the movement of one of said elements to adjust said portion to eifect a desired rate of member movement, and means automatically operative through .the other of said elements in accordance with `a change in some of the operating conditions of said machine tool, whereby to adjust said portion to maintain said rate in spite of said change in operating" conditions.

31. In a machine'tool, the combination of va movable member, a transmission therefor including adjustable rate change means, manual means for adjusting said rate change'means to approximately predetermine a desired rate, other` means movable in one or-the other direction -in accordance with changes in lsome of the operating conditions oi said machine tool, and means connecting said other means for further` adjust-I preventing or permitting the adjustment of said rate change means from said other means.

' 33. lIn a machine tool, the combination oi a movable member, a transmission therefor including a hydraulic motor and a' duid pump connected for operation ot safd motor, said pump being ad- ,instable to various positions for a variety of rates of said member, manual means for adjusting said pump to approximately determine a` desired rate of said member, means movable in onel or the other direction in accordance with changes in the rate etl'ect of said pump and means connecting said movablev means Vfor further adjustment of said pump to maintain a selected member rate substantially constant in spite of variations in some of the operating conditions of said machine tool.

34. In a machine tool, the combination of a movable member, a transmission therefor including a hydraulic motor and an adjustable pump connected for operation of said motor,manual means for adjusting said pump, other means for :further adjusting said pump in accordance with variations in some of the operating conditions of said machine tool, and means alternatively adjustable'for selectively preventing or permitting the adjustment of said pump from said other means.

Y 35. In a machine tool, the combination of a movable member, a transmission for movement thereof including a fluid operable portion in part adjustable to change the rate of support movement, a manual means movable for adjustment of said portion to select a desired rate of support movement, and other control means continuously operative in accordance with variations in some of the operating conditions of said machine tool, said other control means being operative to adjust said portion to. maintain a desired rateof support movement in spite of said variations.

36. In a machine tool, the combination of a movable member, a transmission for movement thereof including a fluid operable portion adjustable to change the rate of support movement. a manually operable means fork adjustment of said portion for a desired rate of support movement, and control means operativeA in accordance with Avariations in some of the operating conditions of la rotatable tool spindle, a support movable in a path transverse to the spindle axis, a spindle transmission including a power source, and a rate changer, a support transmission having a,hy-

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draulically operable portion and driven from said spindle transmission exclusive of said rate changer, said hydraulically operable portion being in part adjustable for changing the rate of support movement, manually operable means for adjusting said portion for a desired rate, control means operative in accordance with variations in some of the operating conditions of said milling machine, and means operative from said control means to-i'urther adjust said portion to maintain a selected support rate substantially constant in spite of said variations in operating conditions.

38. In a milling machine, the combination of a rotatable tool spindle, a support movable in a path transverse to the spindle axis, a spindle transmission including a power source and a rate changer, a support transmission having a hy-A draulically operable portion and driven from said operable portion, a hand lever operable for saidA adjustment through one of said elements, means visibly indicating various support rates resulting from various positions of said lever when said milling machine is operated under certain operating conditions, and control means operable iii accordance with changes in some o! said operating conditions and operative through the other of said elements to effect another rate change adjustment of said hydraulically operable portion, -whereby to substantially maintain the support rate indicated by said indicating means in spite of said changes in some oi' said operating conditions` 39. In a machine tool, the combination of a movable member, a transmissionv therefor including a hydraulic portion adjustable for changing the rate of member movement, and a plurality of means simultaneously available for rate change adjustment of said hydraulic portion, one oi' said means including a manually movable element and a chart movable relative thereto for indicating various rates of member movement, and the other of said means including a device operable in accordance with changes in some of the operating conditions of said machine tool, the last mentioned means being connected for rate change adjustment in a manner adapted to substantially maintain the rate indicated by the position of said element relative to said chart and in various y of the relative element and chart positions irrespectivev of said variations in the operating conditions of said machine tool.

FRED A. PARSONS. 

